Questions

• List out some of the extra features in Java 8 ?

  • Lambda Expressions: Concise functional code using .
  • Functional Interfaces: Single-method interfaces.
  • Introduced and Improved APIs:
  • Stream API: Efficient Data Manipulation.
  • Date/Time API: Robust Date and Time Handling.
  • Collection API Improvements: Enhanced Methods for Collections (e.g., removeIf, replaceAll).
  • Concurrency API Improvements: New classes for parallel processing (e.g., CompletableFuture).
  • Optional Class: Handle null values safely.
  • forEach() Method in Iterable Interface: Executes an action for each element in a Collection.
  • Default Methods: Evolve interfaces without breaking compatibility.
  • Static Methods: Allows adding methods with default implementations to interfaces.
  • Method References: Refer to methods easily.

• explain lambda function ?

• explain functional interface ?

• can functional interface HAVE static / default method ? ( It can have any number of default, static methods but can contain only one abstract method.)

• intermediate vs terminal operation

• map vs flatMap

• predicate ,BiPredicate, function ,BiFunction, consumer, BiConsumer

• findFirst vs findAny

• IntStream explain

• difference between boxed vs map ( boxed is specifically stream of primitve values to stream of their corresponding wrapper classes .)

• Explain optional and provide some method.

• collection vs stream

• reduce()

• stream vs parallel stream

• list all built on functional interfaces

• what is metaspace > permGen vs metaspace

• can we extend the functional interfaces to another interface ?

• what is default methods in java8?

• how to create stream

• how to convert to stream to list

• how to convert stream to integer

• how to convert list to stream